Treatment of gasoline



aaoasri or case .loseph h. @lienlceh, co, llllL, assignor to lilniversal on lProduota Company, @hicago, llllL, a

corporation oi mcvvare No Drawing. Application Feby 29, 1940, Serial No. 321,5l3

l5 lDlas.

This invention relates to a method for improving the stability of hydrocarbon distillates insofar as color and gum formation are concerned. More particularly the process concerns improved methods of preventing deterioration of cracked gasolines which maybe stored. over relatively long periods of time in the presence of air.

The use of inhibitors to prevent the depreciation of olefin-containing hydrocarbon distillates such as cracked gasoline has been practiced. Such compounds as alkyl-substituted phenols, aminophenols, fractions of wood tar distillates, etc., have been added to cracked gasoline in relatively minor quantities, of the order of 01301- .l% to inhibit the formation of objectionable oxidation products and prevent loss of color and antilmock properties of said gasolines during storage periods. The use of inhibitors has replaced or supplemented such forms of refining as acidtreating, clay-treating and the like. The result has been a material saving in refining costs as well as the conservation of substantial amounts of gasoline which were formerly lost in the refining steps.

The present invention offers a means of improving the inhibiting properties of gasoline gum inhibitors and of efiecting material savings in the quantities of such materials which may be required adequately topreserve the valuble properties of gasoline.

In one specific embodiment the present invention comprises a method for treating olefin-containing hydrocarbon distillate such as cracked gasoline to preserve the valuble properties thereof which consists in adding to said distillate a gasoline gum inhibitor together with a relatively minor quantity of an hydroxy-alkyl-substituted alkylene diamine.

The compounds have the general structural formula:

wherein R is an hydroxy-alkyl group, R is a hydrogen atom or an hydroxy-alkylgroup and :c is an integer. A representative compound is hydroxyethyl ethylene diamine.

The present class of compounds are used in combination with known gasoline gum inhibitors such as N-substituted alkyl amino-phenols, alkyl phenols. substituted phenol others, fractions of wood tar distillate boiling in the range of approximately Zed-280 C; and others. The com- 'z-t this invention may be added to the Bil gasoline separately or simultaneously with the gum inhibitor, or may be mixed with the gum inhibitor and the mixture added to the gasoline.

The quantity of hydroxy-alkyl-substituted alkylene diamine commonly used in the gasoline is of the order of 0.001-0.01% by weight of the gasoline. The exact quantity required is a function of the inhibitor with which it is used and of the gasoline as well as the desired stability of the gasoline treated. The compounds of this invention are not of themselves gum inhibitors and the effect observed is not therefore the additive eflect such as might be expected by the joint use of two gasoline gum inhibitors.

When the present class of compounds are added alone to cracked gasoline in amounts up to approximately 0.1%, little or no increase in the oxygen bomb induction period is to be ob served and storage tests indicate that no protection is obtained for the gasoline under storage conditions. However, when used with an inhibitor, the induction period with a given quantity of a gum inhibitor is markedly increased and with the more effective compounds of this invention, more than equal weight percentages of the inhibitor can be replaced without suffering a loss in inhibitor potency. This will be brought out more fully in the examples to be given later.

The compounds of this invention are not necessarily exactly equivalent in their effects and it should be understood that they cannot necessarily be used to replace one another in the composite inhibitor with equal efiects either on a weight or a molal equivalent basis.

The following example is given to illustrate the usefulness and practicability of the process, but should not be construed as limiting it to the exact conditions or compounds given therein.

A Pennsylvania cracked gasoline was treated with a gum inhibitor comprising N-butyl aminophenol in a concentration of 0.01%. The gasoline had an oxygen bomb induction period originally of minutes which was increased to 330 minutes with the inhibitor. To the inhibited gasoline was added 0.01% of'hydroxyethyl eth-'- ylene diamlne and the gasoline had a resultant induction period of 595 minutes. When hydroxyethyl ethylene diamine was added to the uninhibited gasoline, the induction period was 1001 minutes.

I claim as my invention: 1. A process for treating olefin-containing hydrocarbon distillate to prevent depreciation thereof which comprises adding to said distillate a aasoline cum inhibitor and an hydroxy-almlsubstituted allwlene diamine.

53. ll process for treahne craclred gasoline to prevent depreciation thereof which comprises adding to said gasoline a gasoline cum inhibitor L "llflfi" crashed: gasoline to "heel tlon thereof which comprises a to said spline a gasoline cum aihibitor not compound following: ral ctruo for treating crashed gasoline to IEtllfiftlflll thereof which comprises 1g thereto a gasoline sum inhibitor and a c quantity oi lilydroxyethyl ethylene dilor treating cracked gasoline to relation thereof which comprises adding thereto a gasoline cum inhibitor and an amount of an hydroxy-alkyl-substltuted allrylene cliamiue wi 11in the limits oi approximately uhtlllaml it Weight oi the gasoline.

ll process for treating craclred gasoline to prevent depreciation thereof which comprises adding thereto a gasoline cum inhibitor in amounts of approximately 0.001411% and an amount of an hydroxy-allryl-substltuted-allrylene diamine within the limits of approximately U.Ull0l-0.01%, both by weight oi the gasoline.

'2. a process for treating cracked gasoline to prevent depreciation thereof Whicln'comprlses adding to said gasoline a, gasoline gum inhibitor consisting oi." an N-substituted-allryl amlnophenol and an hydroxy-allryl-substltuted allrylene diamine.

d. A process for treating cracked gasoline to prevent depreciation thereof which comprises adding to said gasoline a gasoline sum inhibitor consisting of a wood tar fraction boiling Within the limits oi approximately 240-280 C. and an hydroxyethyl-substituted allrylene diamine.

a an inhibitor for cracked gasoline comprising" a mixture of a gasoline cum inhibitor and an hydrorey-allryl-substituted alkylene dlamlne.

1d. inhibitor for cracked gasoline Which comprises essentially a mixture of an ill-substituted-allryl-aminophenol with an hydroxy-alkyL substituted allrylene diamine.

ii an inhibitor for cracked gasoline which rises essentially a mixture of a Wood tar disioilinc Within the limits of approximately o-aao l3. and an hydroxy-allryl-substituted ale diamine. a composition of matter useful for inhibiting", the oxidation of unstable organic substances such as olefin-containing hydrocarbon distillates which comprises a mixture of an antioxidant with an hydroxy-allryl-substituted allrylene diamine.

l3. a composition of matter useful for preventing oxidation of unstable organic substances which comprises a mixture oi an antioxidant with hydroxyethyl ethylene diamine.

1a. In the art of stabilizing oleflnic dlstillates against deterioration by the addition of gum inhibitors thereto, the method of increasing the .gum inhibiting potency of the inhibitor which 

